Content-Modification System with Fingerprint Data Mismatch and Responsive Action Feature

ABSTRACT

In one aspect, a method includes receiving query fingerprint data representing content received by a content-presentation device. The method also includes comparing at least a first portion of the query fingerprint data with at least one first reference fingerprint data set, where each first reference fingerprint data set corresponds with a respective channel. The method also includes determining that the query fingerprint data does not match any of the at least one first reference fingerprint data sets. The method also includes responsive to the determining, comparing at least a second portion of the query fingerprint data with second reference fingerprint data representing a modifiable content-segment. The method also includes detecting a match between at least the second portion of the query fingerprint data and the second reference fingerprint data. The method also includes responsive to detecting the match, performing an action that facilitates the content-presentation device performing a content-modification operation.

RELATED DISCLOSURES

This disclosure claims priority to U.S. Provisional Pat. App. No. 62/846,425 filed May 10, 2019, which is hereby incorporated by reference herein in its entirety.

USAGE AND TERMINOLOGY

In this disclosure, unless otherwise specified and/or unless the particular context clearly dictates otherwise, the terms “a” or “an” mean at least one, and the term “the” means the at least one.

SUMMARY

In one aspect, a method includes receiving query fingerprint data representing content received by a content-presentation device. The method also includes making a first comparison of at least a first portion of the received query fingerprint data with at least one first reference fingerprint data set, where each of the at least one first reference fingerprint data sets corresponds with a respective channel identifier. The method also includes based on the first comparison, determining that the received query fingerprint data does not match any of the at least one first reference fingerprint data sets. The method also includes responsive to the determining, making a second comparison of at least a second portion of the received query fingerprint data with second reference fingerprint data representing a modifiable content-segment. The method also includes based on the second comparison, detecting a match between at least the second portion of the received query fingerprint data and the second reference fingerprint data. The method also includes responsive to detecting the match, performing an action that facilitates the content-presentation device performing a content-modification operation.

In another aspect, a non-transitory computer-readable storage medium has stored thereon program instructions that, upon execution by a processor, cause performance of a set of operations. The set of operations includes receiving query fingerprint data representing content received by a content-presentation device. The set of operations also includes making a first comparison of at least a first portion of the received query fingerprint data with at least one first reference fingerprint data set, where each of the at least one first reference fingerprint data sets corresponds with a respective channel identifier. The set of operations also includes based on the first comparison, determining that the received query fingerprint data does not match any of the at least one first reference fingerprint data sets. The set of operations also includes responsive to the determining, making a second comparison of at least a second portion of the received query fingerprint data with second reference fingerprint data representing a modifiable content-segment. The set of operations also includes based on the second comparison, detecting a match between at least the second portion of the received query fingerprint data and the second reference fingerprint data. The set of operations also includes responsive to detecting the match, performing an action that facilitates the content-presentation device performing a content-modification operation.

In another aspect, a computing system includes a processor and a non-transitory computer-readable storage medium, having stored thereon program instructions that, upon execution by the processor, cause performance of a set of operations. The set of operations includes receiving query fingerprint data representing content received by a content-presentation device. The set of operations also includes making a first comparison of at least a first portion of the received query fingerprint data with at least one first reference fingerprint data set, where each of the at least one first reference fingerprint data sets corresponds with a respective channel identifier. The set of operations also includes based on the first comparison, determining that the received query fingerprint data does not match any of the at least one first reference fingerprint data sets. The set of operations also includes responsive to the determining, making a second comparison of at least a second portion of the received query fingerprint data with second reference fingerprint data representing a modifiable content-segment. The set of operations also includes based on the second comparison, detecting a match between at least the second portion of the received query fingerprint data and the second reference fingerprint data. The set of operations also includes responsive to detecting the match, performing an action that facilitates the content-presentation device performing a content-modification operation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified block diagram of an example content-modification system in which various described principles can be implemented.

FIG. 2 is a simplified block diagram of an example computing system in which various described principles can be implemented.

FIG. 3 is a diagram of example linear sequences of content and related concepts.

FIGS. 4A, 4B, 4C, 4D, 4E, and 4F collectively make up a table showing example time-periods and corresponding operations that can be performed in connection with the example content-modification system.

FIG. 5 is a flow chart of an example method.

DETAILED DESCRIPTION I. Overview

To deliver and present content to end-users, a content provider can transmit the content to one or more content-distribution systems, each of which can in turn transmit the content to one or more respective content-presentation devices to be output for presentation to respective end-users. Such a hierarchical arrangement can facilitate convenient, widespread distribution of content.

By way of example, in order for a video content provider to deliver video content to end-users throughout the United States, the video content provider can transmit the video content by satellite or another medium to content-distribution systems that serve respective designated market areas (DMAs) within the United States. Each such content-distribution system can therefore receive the national satellite feed carrying the video content and can transmit the video content to television sets and/or set-top boxes in the content-distribution system's DMA, such that the video content can be output for presentation to respective end-users in that DMA. In practice, these content-distribution systems and their means of transmission to content-presentation devices can take various forms. For instance, a content-distribution system can be associated with a cable-television provider and can transmit video content to content-presentation devices of end-users who are cable-television subscribers through hybrid fiber/coaxial cable connections.

As such, in various scenarios, a content-distribution system can transmit content to a content-presentation device, which can receive and output the content for presentation to an end-user. In some situations, even though the content-presentation device receives content from the content-distribution system, it can be desirable for the content-presentation device to perform a content-modification operation so that the content-presentation device can output for presentation alternative content instead of at least a portion of that received content.

For example, in the case where the content-presentation device receives a linear sequence of content segments that includes a given advertisement segment positioned somewhere within the sequence, it can be desirable for the content-presentation device to replace the given advertisement segment with a different advertisement segment that is perhaps more targeted to the end-user (e.g., more targeted to the end-user's interests, demographics, etc.). This type of advertisement replacement is also referred to herein as “dynamic ad replacement (DAI).” As another example, it can be desirable for the content-presentation device to overlay on the given advertisement segment, overlay content that enhances the given advertisement segment in a way that is again perhaps more targeted to the end-user. The described content-modification system can facilitate providing these and other related features.

To help prepare and provide modified content for an end-user, components of the disclosed content-modification system can perform fingerprinting on content accessed at various points within the content-modification system, thereby generating fingerprint data that represents the accessed content. For example, a content-distribution system can access and fingerprint content upstream (e.g., content that the content-distribution system is or will soon transmit over a channel) and/or the content-presentation device can access and fingerprint content farther downstream (e.g., content received by the content-presentation device). The content-modification system can compare fingerprint data to detect matches between them, which can help the content-modification system identify where within a linear sequence of content segments to make a modification, such as where to place targeted content. Further, in scenarios where the channel on which the content-presentation device is receiving content is unknown, fingerprint matching can be used to identify the channel. Once the channel is identified, the content-modification system can identify an upcoming content modification opportunity within the linear sequence of content segments on the identified channel and the content-presentation device can perform a content-modification operation (e.g., DAI) in connection with that opportunity.

In one example, fingerprint matching can be performed by a fingerprint-matching server of the disclosed content-modification system. By way of example, the fingerprint-matching server can receive, from one or more content-distribution systems, reference fingerprint data representing content being transmitted on an identified channel (e.g., a channel identified by metadata associated with the content being transmitted) and can also receive query fingerprint data representing content being received by the content-presentation device on an unidentified channel. As such, the fingerprint-matching server can compare the reference fingerprint data with query fingerprint data to determine whether there is a match. To facilitate this, the fingerprint-matching server might compare the query fingerprint data to one or more reference fingerprint data sets, each associated with a respective channel, until a match is detected. The match between the query fingerprint data and particular reference fingerprint data can enable the fingerprint-matching server to identify the channel.

To identify a content modification opportunity on the identified channel, the fingerprint-matching server can then compare fingerprint data representing a modifiable content-segment (e.g., a replaceable advertisement segment) to fingerprint data representing content transmitted by a content-distribution system on the identified channel. If a match is detected, the fingerprint-matching server can determine that the modifiable content-segment is being broadcast to the content-presentation device on the identified channel, and therefore can identify an upcoming content modification opportunity on the identified channel and facilitate preparing the content-presentation device to perform a content-modification operation in connection with the identified upcoming content modification opportunity.

In practice, there can be a transmission delay between when the content-distribution system transmits the content to the content-presentation device and when the content-presentation device receives the content. This delay can enable the fingerprint-matching server to know what content is being broadcast to the content-presentation device before the content-presentation device receives the content. Thus, by comparing the fingerprint data representing the modifiable content-segment with fingerprint data representing content transmitted by a content-distribution system (as opposed to comparing it to fingerprint data representing content received by the content-presentation device), the fingerprint-matching server has more time to prepare the content-presentation device for performing a content-modification operation with respect to the modifiable content-segment. This can be particularly important in preparing the content-presentation device for performing a content-replacement operation, since the content-presentation device needs to be ready to begin replacing the modifiable content-segment with replacement content at the time-point at which the modifiable content-segment would have otherwise started.

However, there can be situations in which the fingerprint-matching server does not detect a match between the reference fingerprint data representing content being transmitted on an identified channel and the query fingerprint data representing content being received by the content-presentation device on an unidentified channel, and thus cannot identify the channel. As a result, the fingerprint-matching server might not be able to go through the above-described process to identify a content modification opportunity on that channel or prepare the content-presentation device to perform a content-modification operation on that channel.

Accordingly, the present disclosure provides systems and methods that improve the content-modification process, namely by facilitating performance of a content-modification operation in the event that the fingerprint-matching server does not identify the channel on which the content-presentation device is receiving content. In particular, if the fingerprint-matching server determines that the query fingerprint data representing content received by the content-presentation device does not match any reference fingerprint data that corresponds with a known channel identifier, the fingerprint-matching server can responsively compare at least a portion of the query fingerprint data with reference fingerprint data that represents a modifiable content-segment. And in response to the fingerprint-matching server detecting a match between at least a portion of the query fingerprint data and the reference fingerprint data that represents the modifiable content-segment, the fingerprint-matching server can perform an action that facilitates the content-presentation device performing a content-modification operation in connection with the modifiable content-segment.

In other words, when the fingerprint-matching server cannot identify the channel using the query fingerprint data that represents content received by the content-presentation device, the fingerprint-matching server can instead compare that query fingerprint data directly to a database of modifiable content-segments, thus providing another way for the fingerprint-matching server to find out whether the content-presentation device is receiving content that can be modified. Thus, the disclosed systems and methods advantageously provide a way for the content-modification system to deliver targeted content to end-users in situations that might have otherwise prevented the content-modification system from delivering targeted content to those end-users.

Because of the transmission delay described above, and because the disclosed systems and methods involve comparing reference fingerprint data that represents the modifiable content-segment with fingerprint data representing content received by the content-presentation device (as opposed to comparing it to fingerprint data representing content transmitted by a content-distribution system), the fingerprint-matching server might not have time to prepare the content-presentation device for a content-replacement operation. For example, by the time the fingerprint-matching server determines that the content-presentation device is receiving or has received the modifiable content-segment, the content-presentation device might have already begun presenting the modifiable content-segment. Fortunately, however, there can still be time for the content-presentation device to perform a different type of content-modification operation with respect to the modifiable content-segment, such as DAI or another type of content-overlay operation.

Thus, in situations where a channel is not identified and a content-replacement operation might not be possible, the disclosed systems and methods effectively and advantageously enables the fingerprint-matching server to identify a content modification opportunity and prepare a content-presentation device to act on that opportunity using a different type of content-modification operation.

It should be understood, however, that there might be situations where the channel is not identified but there is still enough time to perform a content-replacement operation. As such, the disclosed systems and methods can involve facilitating the content-presentation device performing a content-replacement operation.

II. Architecture

A. Content-Modification System

FIG. 1 is a simplified block diagram of an example content-modification system 100. The content-modification system 100 can include various components, such as a content-distribution system 102, a content-presentation device 104, a fingerprint-matching server 106, a content-management system 108, a data-management system 110, and/or a supplemental-content delivery system 112.

The content-modification system 100 can also include one or more connection mechanisms that connect various components within the content-modification system 100. For example, the content-modification system 100 can include the connection mechanisms represented by lines connecting components of the content-modification system 100, as shown in FIG. 1.

In this disclosure, the term “connection mechanism” means a mechanism that connects and facilitates communication between two or more components, devices, systems, or other entities. A connection mechanism can be or include a relatively simple mechanism, such as a cable or system bus, and/or a relatively complex mechanism, such as a packet-based communication network (e.g., the Internet). In some instances, a connection mechanism can be or include a non-tangible medium, such as in the case where the connection is at least partially wireless. In this disclosure, a connection can be a direct connection or an indirect connection, the latter being a connection that passes through and/or traverses one or more entities, such as a router, switcher, or other network device. Likewise, in this disclosure, communication (e.g., a transmission or receipt of data) can be a direct or indirect communication.

The content-modification system 100 and/or components thereof can take the form of a computing system, an example of which is described below.

Notably, in practice, the content-modification system 100 is likely to include many instances of at least some of the described components. For example, the content-modification 100 is likely to include many content-distribution systems and many content-presentation devices.

B. Computing System

FIG. 2 is a simplified block diagram of an example computing system 200. The computing system 200 can be configured to perform and/or can perform one or more operations, such as the operations described in this disclosure. The computing system 200 can include various components, such as a processor 202, a data-storage unit 204, a communication interface 206, and/or a user interface 208.

The processor 202 can be or include a general-purpose processor (e.g., a microprocessor) and/or a special-purpose processor (e.g., a digital signal processor). The processor 202 can execute program instructions included in the data-storage unit 204 as described below.

The data-storage unit 204 can be or include one or more volatile, non-volatile, removable, and/or non-removable storage components, such as magnetic, optical, and/or flash storage, and/or can be integrated in whole or in part with the processor 202. Further, the data-storage unit 204 can be or include a non-transitory computer-readable storage medium, having stored thereon program instructions (e.g., compiled or non-compiled program logic and/or machine code) that, upon execution by the processor 202, cause the computing system 200 and/or another computing system to perform one or more operations, such as the operations described in this disclosure. These program instructions can define, and/or be part of, a discrete software application.

In some instances, the computing system 200 can execute program instructions in response to receiving an input, such as an input received via the communication interface 206 and/or the user interface 208. The data-storage unit 204 can also store other data, such as any of the data described in this disclosure.

The communication interface 206 can allow the computing system 200 to connect with and/or communicate with another entity according to one or more protocols. Therefore, the computing system 200 can transmit data to, and/or receive data from, one or more other entities according to one or more protocols. In one example, the communication interface 206 can be or include a wired interface, such as an Ethernet interface or a High-Definition Multimedia Interface (HDMI). In another example, the communication interface 206 can be or include a wireless interface, such as a cellular or WI-FI interface.

The user interface 208 can allow for interaction between the computing system 200 and a user of the computing system 200. As such, the user interface 208 can be or include an input component such as a keyboard, a mouse, a remote controller, a microphone, and/or a touch-sensitive panel. The user interface 208 can also be or include an output component such as a display device (which, for example, can be combined with a touch-sensitive panel) and/or a sound speaker.

The computing system 200 can also include one or more connection mechanisms that connect various components within the computing system 200. For example, the computing system 200 can include the connection mechanisms represented by lines that connect components of the computing system 200, as shown in FIG. 2.

The computing system 200 can include one or more of the above-described components and can be configured or arranged in various ways. For example, the computing system 200 can be configured as a server and/or a client (or perhaps a cluster of servers and/or a cluster of clients) operating in one or more server-client type arrangements, for instance.

As noted above, the content-modification system 100 and/or components thereof can take the form of a computing system, such as the computing system 200. In some cases, some or all these entities can take the form of a more specific type of computing system. For instance, in the case of the content-presentation device 104, it can take the form of a desktop computer, a laptop, a tablet, a mobile phone, a television set, a set-top box, a television set with an integrated set-top box, a media dongle, or a television set with a media dongle connected to it, among other possibilities.

III. Example Operations

The content-modification system 100 and/or components thereof can be configured to perform and/or can perform one or more operations. Examples of these operations and related features will now be described.

As noted above, in practice, the content-modification system 100 is likely to include many instances of at least some of the described components. Likewise, in practice, it is likely that at least some of described operations will be performed many times (perhaps on a routine basis and/or in connection with additional instances of the described components).

A. Operations Related to the Content-Distribution System Transmitting Content and the Content-Presenting Device Receiving and Outputting Content

For context, general operations and examples related to the content-distribution system 102 transmitting content and the content-presentation device 104 receiving and outputting content will now be described.

To begin, the content-distribution system 102 can transmit content (e.g., that it received from a content provider) to one or more entities such as the content-presentation device 104. Content can be or include audio content and/or video content, for example. In some examples, content can take the form of a linear sequence of content segments (e.g., program segments and advertisement segments) or a portion thereof. In the case of video content, a portion of the video content may be one or more frames, for example.

The content-distribution system 102 can transmit content on one or more channels (sometimes referred to as stations or feeds). As such, the content-distribution system 102 can be associated with a single channel content distributor or a multi-channel content distributor such as a multi-channel video program distributor (MVPD).

The content-distribution system 102 and its means of transmission of content on the channel to the content-presentation device 104 can take various forms. By way of example, the content-distribution system 102 can be or include a cable-television head-end that is associated with a cable-television provider and that transmits the content on the channel to the content-presentation device 104 through hybrid fiber/coaxial cable connections. As another example, the content-distribution system 102 can be or include a satellite-television head-end that is associated with a satellite-television provider and that transmits the content on the channel to the content-presentation device 104 through a satellite transmission. As yet another example, the content-distribution system 102 can be or include a television-broadcast station that is associated with a television-broadcast provider and that transmits the content on the channel through a terrestrial over-the-air interface to the content-presentation device 104. In these and other examples, the content-distribution system 102 can transmit the content in the form of an analog or digital broadcast stream representing the content.

The content-presentation device 104 can receive content from one or more entities, such as the content-distribution system 102. In one example, the content-presentation device 104 can select (e.g., by tuning to) a channel from among multiple available channels, perhaps based on input received via a user interface, such that the content-presentation device 104 can receive content on the selected channel.

In some examples, the content-distribution system 102 can transmit content to the content-presentation device 104, which the content-presentation device 104 can receive, and therefore the transmitted content and the received content can be the same. However, in other examples, they can be different, such as where the content-distribution system 102 transmits content to the content-presentation device 104, but the content-presentation device 104 does not receive the content and instead receives different content from a different content-distribution system.

The content-presentation device 104 can also output content for presentation. As noted above, the content-presentation device 104 can take various forms. In one example, in the case where the content-presentation device 104 is a television set (perhaps with an integrated set-top box and/or media dongle), outputting the content for presentation can involve the television set outputting the content via a user interface (e.g., a display device and/or a sound speaker), such that it can be presented to an end-user. As another example, in the case where the content-presentation device 104 is a set-top box or a media dongle, outputting the content for presentation can involve the set-top box or the media dongle outputting the content via a communication interface (e.g., an HDMI interface), such that it can be received by a television set and in turn output by the television set for presentation to an end-user.

As such, in various scenarios, the content-distribution system 102 can transmit content to the content-presentation device 104, which can receive and output the content for presentation to an end-user. In some situations, even though the content-presentation device 104 receives content from the content-distribution system 102, it can be desirable for the content-presentation device 104 to perform a content-modification operation so that the content-presentation device 104 can output for presentation alternative content instead of at least a portion of that received content.

For example, in the case where the content-presentation device 104 receives a linear sequence of content segments that includes a given advertisement segment positioned somewhere within the sequence, it can be desirable for the content-presentation device 104 to replace the given advertisement segment with a different advertisement segment that is perhaps more targeted to the end-user (i.e., more targeted to the end-user's interests, demographics, etc.). As another example, it can be desirable for the content-presentation device 104 to overlay on the given advertisement segment, overlay content that enhances the given advertisement segment in a way that is again perhaps more targeted to the end-user. The described content-modification system 100 can facilitate providing these and other related features.

As noted above, in one example, content can take the form of a linear sequence of content segments. As such, in one example, the content-distribution system 102 can transmit a linear sequence of content segments. This is referred to herein as a “transmission sequence.” Likewise, the content-presentation device 104 can receive a linear sequence of content segments. This is referred to herein as a “receipt sequence.” In line with the discussion above, the transmission sequence and the receipt sequence can be the same or they can be different.

FIG. 3 illustrates some examples of these concepts. In one example, the transmission sequence is the TRANSMISSION SEQUENCE 302 shown in FIG. 3. As shown, the TRANSMISSION SEQUENCE 302 includes a PROGRAM SEGMENT A, followed by an AD SEGMENT B, followed by AD SEGMENT C.

Likewise, in one example, the receipt sequence is the RECEIPT SEQUENCE 304 shown in FIG. 3. In this example, the content-distribution system 102 transmits the TRANSMISSION SEQUENCE 302 to the content-presentation device 104, which the content-presentation device 104 receives as the RECEIPT SEQUENCE 304, and therefore the TRANSMISSION SEQUENCE 302 and the RECEIPT SEQUENCE 304 are the same. As such, as shown, the RECEIPT SEQUENCE 304 also includes the PROGRAM SEGMENT A, followed by the AD SEGMENT B, followed by the AD SEGMENT C.

In FIG. 3, the transmission time of the TRANSMISSION SEQUENCE 302 and the receipt time of the RECEIPT SEQUENCE 304 are shown by way of their relationship to a TIMELINE 350. Notably, the transmission time and the receipt time are offset from each other due to a content-transmission delay, which is described in greater detail below.

As noted above, in some situations, even though the content-presentation device 104 receives content from the content-distribution system 102, it can be desirable for the content-presentation device 104 to perform a content-modification operation so that the content-presentation device 104 can output for presentation alternative content instead of at least a portion of that received content. For example, in the case where the content-presentation device 104 receives the receipt sequence, rather than outputting for presentation the receipt sequence, the content-presentation device 104 can output for presentation a modified version of the receipt sequence instead. This is referred to herein as a “modified sequence.”

For example, in the case where the receipt sequence includes a given advertisement segment positioned somewhere within the receipt sequence, it can be desirable for the content-presentation device 104 to replace the given advertisement segment with a different advertisement segment that is perhaps more targeted to the end-user (i.e., more targeted to the end-user's interests, demographics, etc.), thereby resulting in a modified sequence that the content-presentation device 104 can output for presentation.

To illustrate this, in one example, the modified sequence is the FIRST MODIFIED SEQUENCE 306 shown in FIG. 3. As shown, the FIRST MODIFIED SEQUENCE 306 includes the PROGRAM SEGMENT A, followed by the AD SEGMENT D (which replaced the AD SEGMENT B), followed by AD SEGMENT C.

As another example, it can be desirable for the content-presentation device 104 to overlay, on the given advertisement segment, overlay content that enhances the given advertisement segment in a way that is again perhaps more targeted to the end-user, thereby resulting in a modified sequence that the content-presentation device 104 can output for presentation.

To illustrate this, in another example, the modified sequence is the SECOND MODIFIED SEQUENCE 308 shown in FIG. 3. As shown, the SECOND MODIFIED SEQUENCE 308 includes the PROGRAM SEGMENT A, followed by the AD SEGMENT B′ (which is the AD SEGMENT B modified with overlay content), followed by AD SEGMENT C.

Other portions of FIG. 3 will be described later in this disclosure as related concepts are introduced and described.

Moving on in view of the context provided above, FIGS. 4A, 4B, 4C, 4D, 4E, and 4F, collectively make up a table showing example time-periods and corresponding operations that can be performed in connection with the content-modification system 100. These and other related operations will now be described.

B. Operations Related to the Content-Distribution System Transmitting First Content on a Channel

During a time-period T1, the content-distribution system 102 can transmit content on a channel to the content-presentation device 104. This content is referred to herein as “first content.” In one example, the first content is the FIRST CONTENT 310 shown in FIG. 3.

During a time-period T2, the content-distribution system 102 can generate fingerprint data representing the first content. This fingerprint data is referred to herein as “first fingerprint data.” The content-distribution system 102 can generate the first fingerprint data using any content fingerprinting process now known or later developed. An example fingerprint generation technique is described in U.S. Pat. No. 9,495,451 issued Nov. 15, 2016, the entirety of which is hereby incorporated by reference herein. The content-distribution system 102 can generate first fingerprint data at a given rate, such as at the rate of one fingerprint per frame of the first content. The first fingerprint data can be or include some or all of these generated fingerprints.

The content-distribution system 102 can access the first content at various points within the content-distribution system 102. As one example, the content-distribution system 102 can access the first content after it is output by a distribution amplifier within the content-distribution system 102.

Also during the time-period T2, the content-distribution system 102 can generate metadata associated with the first content and/or the first fingerprint data. This metadata is referred to herein as “first metadata.” In one example, the first metadata can be or include a transmission time-stamp, which represents a time-point at which the content-distribution system 102 transmitted the first content. The content-distribution system 102 can determine the transmission time-stamp in various ways, such as based on a time clock that is synchronized to a reference clock.

As another example, the first metadata can be or include a channel identifier, which identifies the channel on which the content-distribution system 102 is transmitting the first content. The content-distribution system 102 can determine the channel identifier in various ways such as based on mapping data that maps the content-distribution system 102 and/or physical inputs and/or outputs within the content-distribution system 102 to respective channel identifiers. In one example, in the case where the content-distribution system 102 transmits content A on channel A, content B on channel B, and content C on channel C, the mapping data can specify which of three different outputs (perhaps on three different distribution amplifiers) maps to which channel identifier, such that the content-distribution system 102 can determine the appropriate channel identifier for content of a given channel.

As another example, the first metadata can be or include SCTE-104 data, a watermark, or a similar type of metadata, any of which can themselves encode other metadata, such as a program identifier, an advertisement identifier (e.g., an industry standard coding identification (ISCI) key), a program genre, or another type of textual or numeric metadata, for instance.

The content-distribution system 102 can associate the first fingerprint data with the first metadata in various ways. For instance, in the case where the first fingerprint data includes multiple fingerprints with each fingerprint representing a corresponding frame of the first content, the content-distribution system 102 can associate each fingerprint with a corresponding transmission time-stamp and/or with other corresponding first metadata.

During a time-period T3, the content-distribution system 102 can transmit the first fingerprint data and the first metadata to the fingerprint-matching server 106. The content-distribution system 102 can transmit the first fingerprint data and the first metadata at a given interval. For example, every two seconds, the content-distribution system 102 can transmit the first fingerprint data and the first metadata that it generated during that most recent two-second time-period.

C. Operations Related to the Content-Presentation Device Receiving Second Content

During a time-period T4, the content-presentation device 104 can receive content from the content-distribution system 102. This content is referred to herein as “second content.” In one example, the second content is the SECOND CONTENT 312 shown in FIG. 3.

During a time-period T5, the content-presentation device 104 can generate fingerprint data representing the second content. This fingerprint data is referred to herein as “second fingerprint data.” The content-presentation device 104 can generate the second fingerprint data using any content fingerprinting process now known or later developed. The content-presentation device 104 can generate the second fingerprint data at various rates, such as at the rate of one fingerprint per frame of the second content. The second fingerprint data can be or include some or all of these generated fingerprints.

The content-presentation device 104 can access the second content at various points within the content-presentation device 104. As one example, the content-presentation device 104 can access the second content as it is being received by an input buffer (e.g., an HDMI buffer) of the content-presentation device 104. In another configuration, the content-presentation device 104 can access the second content as it is being received by a display buffer of the content-presentation device 104. In this configuration, the second content can therefore be content that the content-presentation device 104 not only receives, but also outputs for presentation.

Also during the time-period T5, the content-presentation device 104 can generate metadata associated with the second content and/or the second fingerprint data. This metadata is referred to herein as “second metadata.” As one example, the second metadata can be or include a receipt time-stamp, which represents a time-point at which the content-presentation device 104 received the second content. The content-presentation device 104 can determine the receipt time-stamp in various ways, such as based on a time clock that is synchronized to a reference clock. As noted above, the content-presentation device 104 can access the second content at various points within the content-presentation device 104. In one example, the point at which the second content is accessed can be considered the “receipt” point for purposes of determining the receipt time-stamp.

In practice, while the first metadata is likely to be or include a channel identifier, the second metadata is likely to not be nor include a channel identifier.

The content-presentation device 104 can associate the second fingerprint data with the second metadata in various ways. For instance, where the second fingerprint data includes multiple fingerprints with each fingerprint representing a corresponding frame of second content, the content-presentation device 104 can associate each second fingerprint with a corresponding receipt time-stamp and/or other corresponding metadata.

During a time-period T6, the content-presentation device 104 can transmit the second fingerprint data and the second metadata to the fingerprint-matching server 106. The content-presentation device 104 can transmit the second fingerprint data and the second metadata at a given interval. For example, every two seconds, the content-presentation device 104 can transmit the second fingerprint data and the second metadata that it generated during that most recent two-second time-period.

D. Operations Related to Identifying a Channel on which the Content-Presentation Device is Receiving the Second Content

During a time-period T7, the fingerprint-matching server 106 can receive the first fingerprint data and the first metadata from the content-distribution system 102. As noted above, the first fingerprint data represents the first content transmitted by the content-distribution system 102 on the channel. As noted above, the first metadata can, and for the purposes of this described example does, identify the channel. In this way, the first content can be considered as content being transmitted on an identified channel.

During a time-period T8, the fingerprint-matching server 106 can receive the second fingerprint data and the second metadata from the content-presentation device 104. As noted above, the second fingerprint data represents the second content received by the content-presentation device 104. However, as noted above, the associated metadata may not, and for the purposes of this described example does not, identify the channel. In this way, the second content can be considered as content being received on an unidentified channel.

During a time-period T9, the fingerprint-matching server 106 can compare the first fingerprint data and the second fingerprint data to determine whether there is a match. In this disclosure, this type of match attempt, namely a match attempt between (i) reference fingerprint data representing content being transmitted on an identified channel and (ii) query fingerprint data representing content being received on an unidentified channel, is referred to herein as a “cold match attempt.”

During a time-period T10, based on the comparing, the fingerprint-matching server 106 can detect a match between the first fingerprint data and the second fingerprint data. The fingerprint-matching server 106 can compare and/or detect a match between fingerprint data using any content fingerprint comparing and matching technique now known or later developed. An example fingerprint comparing and matching technique is described in U.S. Pat. No. 9,146,990 issued Sep. 29, 2015, the entirety of which is hereby incorporated by reference herein.

To effectively compare the first fingerprint data and the second fingerprint data, the fingerprint-matching server 106 may need to account for a content-transmission delay. For context, in the case where the content-distribution system 102 transmits a given frame of content on a given channel at a time-point A, for various reasons, the content-presentation device 104 may not receive that frame until a time-point B that is later (e.g., ten seconds later) than the time-point A. This type of delay is referred to herein as a “content-transmission delay.”

In one example, the time-point A, the time-point B, and the content-transmission delay can be the TIME-POINT A 314, the TIME-POINT B 316, and the CONTENT-TRANSMIS SION DELAY 318, respectively, shown FIG. 3. Note that FIG. 3 is for illustration purposes and is not necessarily to scale at least with respect to time. In practice, the actual amount of content-transmission delay may be different from the amount shown.

To help the fingerprint-matching server 106 effectively compare the first fingerprint data with the second fingerprint data, the fingerprint-matching server 106 may need to account for such a content-transmission delay. In one example, the fingerprint-matching server 106 can do this by comparing the first fingerprint data that it receives at a receipt time-point with the second fingerprint data that it receives during a time-period defined by a starting time-point and an ending time-point. The starting time-point can be the receipt time-point plus an offset representing an anticipated content-transmission delay (e.g., ten seconds), minus a tolerance a time-period (e.g., two seconds). The ending time-point can be the receipt time-point plus the offset (e.g., ten seconds), plus the tolerance a time-period (e.g., two seconds). As such, in one example where the anticipated content-transmission delay is 10 seconds, the fingerprint-matching server 106 can compare first fingerprint data that it receives at a receipt time-point with second fingerprint data that it receives during a time-period between (i) the receipt time-point plus eight seconds and (ii) receipt time-point plus twelve seconds.

In some cases, the fingerprint-matching server 106 can determine a content-transmission delay, which it can use to select an appropriate offset for use in determining the starting and ending time-points, as described above. The fingerprint-matching server 106 can determine the content-transmission delay in various ways. For example, after the fingerprint-matching server 106 detects a match based on a cold match attempt, the fingerprint-matching server 106 can determine the content-transmission delay as a difference between the corresponding transmission time-stamp (of the first metadata) and the corresponding receipt time-stamp (of the second metadata), for example. Notably, the content-transmission delay can vary from channel to channel.

During a time-period T11, based on the detected match, the fingerprint-matching server 106 can identify the channel on which the second content is being received by the content-presentation device 104. In one example, the fingerprint-matching server 106 can identify the channel based on the channel identifier metadata associated with the first fingerprint data used to detect the match.

Notably, in practice, since there are likely to be multiple potential channels on which the content-presentation device 104 is receiving the second content, the fingerprint-matching server 106 is likely to compare the second fingerprint data with multiple instances of first fingerprint data (each representing a different respective instance of first content on a different respective channel), to determine which of those multiple instances matches the second fingerprint data.

Also, in some cases, the fingerprint-matching server 106 can detect a match between the second fingerprint data and each of multiple instances of first fingerprint data (each representing a different respective instance of first content on a different respective channel). This is referred to herein as a “multimatch scenario” and can occur for various reasons. For example, this can occur when the content-distribution system 102 is transmitting the same or similar content on more than one channel at or about the same time. In this scenario, the fingerprint-matching server 106 can perform additional operations to identity, from among the multiple channels associated with the multimatch scenario, on which specific channel the content-presentation device 104 is receiving the second content. The fingerprint-matching server 106 can do this using any channel multimatch disambiguation technique now known or later developed. An example channel multimatch disambiguation technique is described in U.S. Pat. No. 9,992,533 issued Jun. 5, 2018, the entirety of which is hereby incorporated by reference herein.

E. Operations Related to Determining Historical Content Consumption Data

During a time-period T12, the fingerprint-matching server 106 can generate metadata associated with the identified channel. For example, the metadata can be or include a channel identification time-stamp. The fingerprint-matching server 106 can determine the channel identification time-stamp in various ways, such as based on a time clock that is synchronized to a reference clock. In another example, the metadata can be or include a device identifier that identifies the content-presentation device 104 that is receiving content on the identified channel. The fingerprint-matching server 106 can determine the device identifier in various ways, such as by receiving it from the content-presentation device 104. In another example, the fingerprint-matching server 106 can receive data (e.g., device registration data) from the content-presentation device 104 and can use mapping data to map the received data to determine the device identifier.

During a time-period T13, the fingerprint-matching server 106 can transmit an indication of the identified channel and the associated metadata to the data-management system 110.

During a time-period T14, the data-management system 110 can receive the indication of the identified channel and the associated metadata from the fingerprint-matching server 106.

The data-management system 110 can use the received indication of the identified channel and the associated metadata, perhaps with other data, to determine when the content-presentation device 104 has received content on the identified channel, what specific content the content-presentation device 104 has received, etc. This type of data is referred to herein as “historical content consumption data.”

As such, during a time-period T15, the data-management system 110 can determine historical content consumption data associated with the content-presentation device 104.

F. Operations Related to the Content-Distribution System Transmitting Third Content

As noted above, the fingerprint-matching server 106 can identify the channel on which the content-presentation device 104 is receiving the second content.

During a time-period T16, the content-distribution system 102 can transmit content on the identified channel to the content-presentation device 104. This content is referred to herein as “third content.” In one example, the third content is the THIRD CONTENT 320 shown in FIG. 3. In practice, the content-distribution system 102 is likely to transmit the third content shortly after (e.g., immediately after or a few seconds or minutes after) transmitting the first content.

During a time-period T17, the content-distribution system 102 can generate fingerprint data representing the third content. This fingerprint data is referred to herein as “third fingerprint data.”

Also during the time-period T17, the content-distribution system 102 can generate metadata associated with the third content and/or the third fingerprint data. This metadata is referred to herein as “third metadata.” The content-distribution system 102 can also associate the third fingerprint data with the third metadata.

During a time-period T18, the content-distribution system 102 can transmit the third fingerprint data and the third metadata to the fingerprint-matching server 106.

The content-distribution system 102 can transmit the third content, generate the third fingerprint data, generate the third metadata, associate the third fingerprint data with the third metadata, and transmit the third fingerprint data and the third metadata in various ways, such as ways that are the same as or similar to those described above in connection with transmitting the first content, generating the first fingerprint data, generating the first metadata, associating the first fingerprint data with the first metadata, and transmitting the first fingerprint data and the first metadata.

G. Operations Related to the Content-Management System Receiving a Modifiable Content-Segment

During a time-period T19, the content-management system 108 can receive content in the form of a content segment that has been identified as a candidate to be modified. This content is referred to herein as a “modifiable content-segment” or “fourth content.” In one example, the modifiable content-segment is the MODIFIABLE CONTENT-SEGMENT shown in FIG. 3.

The modifiable content-segment can take various forms. For example, the modifiable content-segment can be an advertisement segment (e.g., a commercial) or a program segment. As such, in one example, the modifiable content-segment can be an advertisement segment that has been identified as a candidate to be modified, perhaps by way of being replaced with a different advertisement segment, and/or by way of having content overlaid thereon.

In one example, a user, perhaps associated with the content-distribution system 102, can facilitate uploading the modifiable content-segment to the content-management system 108, such that the content-management system 108 can receive it in this way.

During a time-period T20, the content-management system 108 can generate fingerprint data representing the modifiable content-segment. This fingerprint data is referred to herein as “fourth fingerprint data.” The content-management system 108 can generate the fourth fingerprint data using any fingerprint generation technique now known or later developed. The content-management system 108 can generate the fourth fingerprint data at a given rate, such as at the rate of one fingerprint per frame of the fourth content. The fourth fingerprint data can be or include some or all of these generated fingerprints.

Also during the time-period T20, the content-management system 108 can generate metadata associated with the modifiable content-segment and/or the fourth fingerprint data. This metadata is referred to herein as “fourth metadata.” As one example, the fourth metadata can be or include a duration of the modifiable content-segment. The content-management system 108 can determine the duration in various ways, such as based on the fingerprint generation process. For example, in the case where the content-management system 108 generating the fourth fingerprint data involves generating one fingerprint per frame, where the modifiable content-segment has a frame rate of 30 frames per second, and where the fingerprinting process results in 300 fingerprints being generated, the content-management system 108 can deduce that the modifiable content-segment has a duration of ten seconds. The metadata can also be or include other information about the modifiable content-segment, such as a content segment identifier, a title, and/or specifics about permissible ways in which the modifiable content-segment can be modified, etc.

During a time-period T21, the content-management system 108 can transmit the fourth fingerprint data and the fourth metadata to the fingerprint-matching server 106.

In practice, the content-management system 108 is likely to receive many modifiable content-segments. In such situations, the content-management system 108 can perform one or more of the operations described above, as appropriate for each of the many received modifiable content-segments. As such, the content-management system 108 can transmit many instances of fourth fingerprint data, each corresponding with a different respective modifiable content-segment, to the fingerprint-matching server 106.

H. Operations Related to the Fingerprint-Matching Server Identifying an Upcoming Content Modification Opportunity on the Identified Channel

During a time-period T22, the fingerprint-matching server 106 can receive the third fingerprint data and the third metadata from the content-distribution system 102. As noted above, the third fingerprint data represents the third content transmitted by the content-distribution system 102 on the identified channel.

During a time-period T23, the fingerprint-matching server 106 can receive the fourth fingerprint data and the fourth metadata from the content-management system 108. As noted above, the fourth fingerprint data represents the modifiable content-segment.

During a time-period T24, the fingerprint-matching server 106 can compare at least a portion of the third fingerprint data with at least a portion of the fourth fingerprint data to determine whether there is a match.

During a time-period T25, based on the comparing, the fingerprint-matching server 106 can detect a match between the at least a portion of the third fingerprint data and the at least a portion of the fourth fingerprint data. The fingerprint-matching server 106 can compare and/or detect a match between fingerprint data using any content fingerprint comparing and matching process now known or later developed.

During a time-period T26, based on the detected match, the fingerprint-matching server 106 can determine that at least a portion of the modifiable content-segment is included within the third content, and therefore can identify an upcoming content modification opportunity on the identified channel. For example, the fingerprint-matching server 106 can determine that at least a beginning portion of the MODIFIABLE CONTENT-SEGMENT is included within the THIRD CONTENT 320, as shown in FIG. 3, and therefore can identify an upcoming content modification opportunity.

As noted above, the fingerprint-matching server 106 can generate third metadata, which can be the same as or similar to the first metadata. As such, the third metadata can be or include a transmission time-stamp and/or a channel identifier, for example. However, the third metadata can also be or include a position of at least a portion of the modifiable content-segment within the third content. In one example, the metadata can specify this using a starting frame marker and an ending frame marker, each corresponding with a respective frame of the third content. The fingerprint-matching server 106 can determine the starting frame marker and the ending frame marker based on the matching.

Notably, in practice, since there are likely to be multiple potential modifiable content-segments where portions thereof could be included within the third content, the fingerprint-matching server 106 is likely to compare at least a portion of the third fingerprint data with at least a portion of multiple instances of fourth fingerprint data (each representing a different respective instance of a modifiable content-segment), to determine which of those multiple instances of the fourth fingerprint data has a portion that matches the at least a portion of the third fingerprint data.

I. Operations Related to Preparing the Content-Presentation Device to Perform a Content-Modification Operation in Connection with the Identified Upcoming Content Modification Opportunity

During a time-period T27, based on the detected match, the fingerprint-matching server 106 can transmit the third fingerprint data and the third metadata to the content-presentation device 104 data to facilitate preparing the content-presentation device 104 to perform a content-modification operation in connection with the identified upcoming content modification opportunity.

During a time-period T28, the content-presentation device 104 can receive the third fingerprint data and the third metadata from the fingerprint-matching server 106.

During a time-period T29, the content-presentation device 104 can receive content on the identified channel. This content is referred to herein as “fifth content.” In one example, the fifth content is the FIFTH CONTENT 324 shown in FIG. 3.

For various reasons (e.g., due to a transmission delay associated with transmitting fingerprint data and metadata being shorter that the content-transmission delay), the content-presentation device 104 can receive the third fingerprint data and the third metadata from the fingerprint-matching server 106 before receiving the fifth content from the content-distribution system 102. In this way, the content-presentation device 104 can receive fingerprint data representing content that the content-presentation device 104 is expecting to receive shortly thereafter, and that the content-presentation device should actually receive shortly thereafter unless an interruption event (e.g., a channel-change event) occurs.

In practice, similar to how the content-distribution system 102 is likely to transmit the third content shortly after (e.g., immediately after or a few seconds or minutes after) transmitting the first content, the content-presentation device 104 is likely to receive the fifth content shortly after (e.g., immediately after or a few seconds or minutes after) receiving the second content.

During a time-period T30, the content-presentation device 104 can output for presentation at least a portion of the fifth content. For example, referring to FIG. 3, the content-presentation device can output for presentation the portion of the FIFTH CONTENT 324 that is the end portion of the PROGRAM SEGMENT A.

As noted above, in some situations, even though the content-presentation device 104 receives content from the content-distribution system 102, it can be desirable for the content-presentation device 104 to perform a content-modification operation so that the content-presentation device 104 can output for presentation alternative content instead of at least a portion of the received content.

As such, even though the content-presentation device 104 receives the fifth content and outputs for presentation at least a portion of the fifth content, it can be desirable for the content-presentation device 104 to perform a content-modification operation so that the content-presentation device 104 can also output for presentation alternative content instead of at least another portion (e.g., the remaining portion) of the fifth content. For example, referring to FIG. 3, it can be desirable for the content-presentation 104 device to replace at least a portion of the AD SEGMENT B with at least a portion of a different advertisement segment that is perhaps more targeted to the end-user. As another example, it can be desirable for the content-presentation device 104 to overlay on at least a portion of the AD SEGMENT B, overlay content that enhances at least a portion of the AD SEGMENT B in a way that is again perhaps more targeted to the end-user.

During a time-period T31, the content-presentation device 104 can generate fingerprint data representing the fifth content. This fingerprint data is referred to herein as “fifth fingerprint data.” The content-presentation device 104 can generate the fifth fingerprint data using any content fingerprinting process now known or later developed. The content-presentation device 104 can generate the fifth fingerprint data at various rates, such as at the rate of one fingerprint per frame of the fifth content. The fifth fingerprint data can be or include some or all of these generated fingerprints.

Also during the time-period T31, the content-presentation device 104 can generate metadata associated with the fifth content and/or the fifth fingerprint data. This metadata is referred to herein as “fifth metadata.”

The content-presentation device 104 can receive the fifth content, generate the fifth fingerprint data, generate the fifth metadata, associate the fifth fingerprint data with the fifth metadata in various ways, such as ways that are the same as or similar to those described above in connection with receiving the second content, generating the second fingerprint data, generating the second metadata, and associating the second fingerprint data with the second metadata.

As noted above, the content-presentation device 104 can receive the third fingerprint data from the fingerprint-matching server 106 and can generate the fifth fingerprint data.

During a time-period T32, the content-presentation device 104 can compare the third fingerprint data and the fifth fingerprint data to determine whether there is a match.

During a time-period T33, based on the comparing, the content-presentation device 104 can detect a match between the third fingerprint data and the fifth fingerprint data. In this disclosure, this type of match attempt, namely a match attempt between (i) reference fingerprint data representing content transmitted by the content-distribution system 102 on an identified channel (at least based on the most recent channel identification analysis), and (ii) query fingerprint data representing content being received by the content-presentation device 104 on the same identified channel, is referred to herein as a “hot match attempt.” The content-presentation device 104 can compare and/or detect a match between fingerprint data using any content fingerprint comparing and matching process now known or later developed.

During a time-period T34, based on the detected match, the content-presentation device 104 can determine a time-point at which the identified upcoming modification opportunity starts. This is referred to herein as the “modification start-time.” In one example, the modification start-time is the MODIFICATION START-TIME 326 as shown FIG. 3.

In one example, the content-presentation device 104 can determine the modification start-time by starting with the transmission time-stamp associated with the starting frame marker (which, as described above, can be or be included in the third metadata) and adding the content-transmission delay to that transmission time-stamp, to arrive at the modification start-time.

As another example, the content-presentation device 104 can determine the modification start-time by first establishing a synchronous lock between the third content, the third fingerprint data, and/or the third metadata on the one hand, and the fifth content, the fifth fingerprint data, and/or the fifth metadata, on the other hand. The content-presentation device 104 can establish the synchronous lock using any synchronous lock technique now known or later developed. An example synchronous lock technique is described in U.S. Pat. No. 10,506,275 issued Dec. 10, 2019, the entirety of which is hereby incorporated by reference herein. Another example synchronous lock technique is described in U.S. Pat. App. Pub. No. 2020/0029108 published Jan. 23, 2020, the entirety of which is hereby incorporated by reference herein.

The content-presentation device 104 can then determine the modification start-time by determining a time-period between (i) a current receipt time-stamp associated with a first portion of the fifth content that the content-presentation device 104 is currently receiving and (ii) based on the synchronous lock, an anticipated receipt time-stamp associated with a second portion of the fifth content that is the start of the modifiable content-segment, and then adding the determined time-period to the current receipt time-stamp, to arrive at the modification start-time.

Also during the time-period T34, based on the detected match, the content-presentation device 104 can determine a time-point at which the identified upcoming modification opportunity ends. This is referred to herein as the “modification end-time.” In one example, the modification end-time is the MODIFICATION END-TIME 328 as shown FIG. 3.

In one example, the content-presentation device 104 can determine the modification end-time by starting with the modification start-time and adding the duration of the modifiable content-segment (which, as described above, can be or be included in the fourth metadata) to the modification start-time, to arrive at the modification end-time.

Notably, if the content-presentation device 104 performs a hot match attempt and does not detect a match, the content-presentation device 104 can determine that the content-presentation device 104 is no longer receiving content on the most recently identified channel. In response, the content-presentation device 104 can repeat one or more of the operations described above so that the fingerprint-matching server 106 can perform another cold match attempt, to attempt to identify the channel again.

During a time-period T35, the content-presentation device 104 can transmit a request for content for use in connection with performing the content-modification operation, to the content-management system 108. This content is referred to herein as “supplemental content.” In one example, the content-presentation device 104 can transmit the request before the modification start-time (e.g., ten seconds before). In some cases, the request can include selection criteria for the supplemental content, which the content-presentation device 104 can determine based on the third metadata that the content-presentation device 104 receives from the fingerprint-matching server 106, for instance.

For example, the selection criteria can specify a requested type of content (e.g., a replacement content segment or overlay content), duration (e.g., 15 seconds, 30 seconds, or 60 seconds), aspect ratio (e.g., 4:3 or 16:9), and/or resolution (e.g., 720p or 1080p).

During a time-period T36, the content-management system 108 can receive the request and use it as a basis to select supplemental content from among multiple supplemental content items that are available for selection. In some cases, the content-management system 108 can receive and consider various data to help inform which supplemental content to select. For example, the content-management system 108 can receive historical content consumption data for the content-presentation device 104 from the data-management system 110 and/or the content-management system 108 can receive demographic data from a demographic data provider. The content-management system 108 can then use at least the received historical content consumption data and/or the received demographic data as a basis to select the supplemental content.

The content-management system 108 can cause the selected supplemental content to be transmitted to the content-presentation device 104. In one example, the content-management system 108 can do this by communicating with a supplemental-content delivery system 112 that can host the supplemental content. The supplemental-content delivery system 112 can take various forms and can include various components, such as a content distribution network (CDN).

During a time-period T37, the content-management system 108 can transmit a request for a link (e.g., a Uniform Resource Identifier (URI) or a Uniform Resource Locator (URL)) pointing to the hosted supplemental content, to the supplemental-content delivery sy stem 112.

During a time-period T38, the supplemental-content delivery system 112 can receive and respond to the request for the link by transmitting the requested link to the content-management system 108.

During a time-period T39, the content-management system 108 can then in turn transmit the link to the content-presentation device 104.

During a time-period T40, the content-presentation device 104 can receive the link, which it can use to retrieve the supplemental content from the supplemental-content delivery system 112, such that the content-presentation device 104 can use the retrieved supplemental content in connection with performing the content-modification operation. In one example, the content-presentation device 104 can retrieve the supplemental content and store the supplemental content in a data-storage unit of the content-presentation device 104.

As such, in some examples, the content-presentation device 104 can receive the modifiable content-segment from one source (e.g., the content-distribution system 102), and the supplemental content from another source (e.g., the supplemental-content delivery system 112). These segments can be transmitted to, and received by, the content-presentation device 104 in different ways. For example, the content-distribution system 102 can transmit, and the content-presentation device 104 can receive, the modifiable content-segment as a broadcast stream transmission, whereas the supplemental-content delivery system 112 can transmit, and the content-presentation device 104 can receive, the supplemental content as an over-the-top (OTT) transmission. In this context, in one example, the content-distribution system 102 can receive the modifiable content-segment via one communication interface (e.g., an HDMI interface), and the content-presentation device 104 can receive the supplemental content via a different communication interface (e.g., an Ethernet or WI-FI interface).

J. Operations Related to the Content-Presentation Device Performing a Content-Modification Operation

At a time-period T41, the content-presentation device 104 can perform the content-modification operation. The content-presentation device 104 can do this in various ways, perhaps depending on the type of content-modification operation to be performed.

In one example, the content-presentation device 104 performing a content-modification operation can involve the content-presentation device 104 modifying the modifiable content-segment by replacing it with supplemental content. This is referred to herein as a “content-replacement operation.” For example, in this scenario, the content-presentation device 104 can receive a linear sequence of content segments that includes the modifiable content-segment and the associated metadata, and can also receive the supplemental content segment, as described above. The content-presentation device 104 can output for presentation the sequence of content segments up until the modification start-time (which corresponds to the start of the modifiable content-segment), at which time the content-presentation device 104 can switch to outputting for presentation the supplemental content instead. Then, at the modification end-time (which corresponds to the end of the modifiable content-segment), the content-presentation device 104 can switch back to outputting for presentation the content that follows in the linear sequence of content segments (or perhaps to other content, such as additional supplemental content that is replacing another modifiable content-segment).

In one example, the operation of the content-presentation device 104 switching from outputting the sequence of content segments to outputting the supplemental content can involve using various buffers of the content-presentation device 104. For example, this can involve the content-presentation device 104 switching from using first data in a first input buffer where the sequence of content segments is being received to using second data in a second input buffer where the supplemental content is being received, to populate a display buffer.

As such, according to one example as illustrated in FIG. 3, by performing a content replacement operation, the content-presentation device 104 can replace the AD SEGMENT B with the AD SEGMENT D. As a result, rather than outputting for presentation the RECEIPT SEQUENCE 304, the content-presentation device can instead output for presentation the FIRST MODIFIED SEQUENCE 306.

In another example, the content-presentation device 104 performing a content-modification operation can involve the content-presentation device 104 modifying a modifiable content-segment by overlaying on the modifiable content-segment, overlay content (referred to herein as a “content-overlay operation”). For example, in this scenario, the content-presentation device 104 can again receive a linear sequence of content segments that includes the modifiable content-segment and the associated metadata, and the content-presentation device 104 can also receive the supplemental content, as described above.

The content-presentation device 104 can then output for presentation the modifiable content-segment as it ordinarily would, except that starting at the modification start-time, the content-presentation device 104 can start overlaying the supplemental content on the modifiable content-segment. The content-presentation device 104 can continue overlaying the supplemental content until the modification end-time. In this way, the content-presentation device 104 can overlay the supplemental content during at least some temporal portion of the modifiable content-segment.

In one example, the operation of the content-presentation device 104 overlaying supplemental content on the modifiable content-segment can involve using various buffers of the content-presentation device 104. For example, this can involve the content-presentation device 104 using a portion of first data in a first input buffer where the sequence of content segments is being received together with second data in a second input buffer where the supplemental content is being received, for the purposes of populating a display buffer. In this way, the content-presentation device can combine relevant portions of the modifiable content-segment (i.e., all portions except those representing region where the supplemental content is to be overlaid) together with the supplemental content to be used as an overlay, to create the desired modifiable content-segment plus the supplemental content overlaid thereon.

As such, according to one example as illustrated in FIG. 3, by performing a content overlay operation, the content-presentation device 104 can overlay supplemental content on the AD SEGMENT B, thereby modifying it to AD SEGMENT B′. As a result, rather than outputting for presentation the RECEIPT SEQUENCE 304, the content-presentation device can instead output for presentation the SECOND MODIFIED SEQUENCE 308.

K. Tracking and Reporting Operation-Related Data

To help facilitate performance of various operations such as the content-presentation device 104 performing a content-modification operation and to help allow for the tracking and reporting of such operations, the content-modification system 100 and/or components thereof can track and report various operation-related data at various times and in various ways.

As just a few illustrative examples, responsive to certain operations being performed, such as those described herein, the fingerprint-matching server 106, the content-presentation device 104, and/or another entity can generate, store, and/or transmit messages that indicate (i) that a modifiable content-segment has been identified, (ii) that a channel has been identified/confirmed (perhaps based on a match detected as a result of a cold or hot match attempt), (iii) that an upcoming content modification opportunity on the identified channel has been identified, (iv) that supplemental content has been requested, (v) that supplemental content has been received, (vi), that a content-modification operation has started, (vii) that a content-modification operation has ended, and/or (viii) that a scheduled content-modification operation was aborted and/or not performed for any given reason. In some cases, these messages can include other metadata related to these operations. For example, the metadata can specify relevant timing information, device identifiers, channel identifiers, content segment identifiers, etc.

L. Watermark-Based Techniques

Although this disclosure has described the content-modification system 100 using fingerprint-based technology to perform various operations and to provide various features, in some examples, the content-modification system 100 can use watermark-based techniques instead of, or in addition to, fingerprint-based techniques, to perform these and other operations and to provide these and other features.

For example, as an alternative to the fingerprint-based technique described above in which the fingerprint-matching server 106 identifies the channel on which the second content is being received by the content-presentation device 104, the content-distribution system 102 or another entity can insert a channel identifier in the form of a watermark into the second content, such that the fingerprint-matching server 106, the content-presentation device 104, or another entity can extract the channel identifier and use it to identify the channel on which the second content is being received by the content-presentation device 104.

In this context, the content-modification system 100 can employ any watermark technique now known or later developed.

M. Operations Related to Responsive Actions in the Event of a Fingerprint Data Mismatch

As discussed above, the present disclosure involves operations that can be performed in the event that the fingerprint-matching server 106 does not identify the channel on which the content-presentation device 104 is receiving content. Examples of these operations will now be described in more detail. Although the following example operations will be described herein primarily as being performed by a fingerprint-matching server 106, other entities of the content-modification system 100 could perform one or more of such operations in alternative embodiments.

The fingerprint-matching server 106 can receive query fingerprint data (e.g., the “second fingerprint data” referenced above) representing content received by the content-presentation device 104 on a channel. In some examples, the content-presentation device 104 can generate the query fingerprint data based on the content it receives from the content-distribution system 102 and can transmit the query fingerprint data to the fingerprint-matching server 106.

The fingerprint-matching server 106 can then make a comparison (also referred to herein as a “first comparison”) of at least a first portion of the received query fingerprint data with at least one reference fingerprint data set (e.g., the “first fingerprint data” referenced above). Each of the at least one reference fingerprint data sets can correspond with a respective channel identifier. This comparison can be performed in the same or similar manner as described above with respect to the cold match attempts and related operations described above (e.g., the operations performed during time-period T9), or with respect to other fingerprint matching scenarios described herein.

In some scenarios, this comparison can be made to a smaller quantity of reference fingerprint data sets (e.g., one reference fingerprint data set or less than ten reference fingerprint data sets). In other scenarios, however, the fingerprint-matching server 106 might need to make numerous (e.g., hundreds) comparisons between the query fingerprint data and a large amount (e.g., hundreds) of reference fingerprint data sets, to determine whether the query fingerprint data matches at least a portion of any of the reference fingerprint data sets.

Based on this comparison, the fingerprint-matching server 106 can determine that the query fingerprint data does not match any of the at least one reference fingerprint data sets. And as discussed above, this can result in the fingerprint-matching server not being able to identify the channel on which the content-presentation device 104 is receiving content and thus not being able to go through the process described above for identifying a content modification opportunity on the channel or prepare the content-presentation device 104 to perform a content-modification operation on that channel. The present disclosure thus provides the following responsive actions that can be performed in the event that this occurs, and these responsive actions advantageously enable a content-modification operation (e.g., DAI) to still be performed despite the content-modification system 100 not being able to identify the channel.

In response to determining that the query fingerprint data does not match any of the at least one reference fingerprint data sets, the fingerprint-matching server 106 can make a comparison (also referred to herein as a “second comparison”) of at least a second portion of the query fingerprint data with reference fingerprint data representing a modifiable content-segment (e.g., the “fourth fingerprint data” referenced above).

As discussed above, the modifiable content-segment can be an advertisement segment (e.g., a commercial) or a program segment that has been identified as a candidate to be modified, perhaps by way of being replaced with a different segment (e.g., a different advertisement segment), and/or by way of having content overlaid thereon. The fingerprint-matching server 106 can receive the reference fingerprint data representing the modifiable content-segment from the content-management system 108 or other component of the content-modification system 100.

In some examples, at least the first portion of the query fingerprint data that the fingerprint-matching server 106 compares to the reference fingerprint data set(s) in performing the first comparison can be the same as at least the second portion of the query fingerprint data that the fingerprint-matching server 106 compares to the reference fingerprint data representing the modifiable content-segment in performing the second comparison. In other examples, the first portion of the query fingerprint data that the fingerprint-matching server 106 uses in performing the first comparison and the second portion of the query fingerprint data that the fingerprint-matching server 106 uses in performing the second comparison might not include any of the same fingerprint data from the query fingerprint data.

Based on this second comparison, the fingerprint-matching server 106 can detect a match between at least the second portion of the query fingerprint data and the reference fingerprint data representing the modifiable content-segment. The fingerprint-matching server 106 can compare and/or detect this match between this query fingerprint data and this reference fingerprint data using any content fingerprint comparing and matching process now known or later developed. By comparing this query fingerprint data to reference fingerprint data representing the modifiable content-segment, the fingerprint-matching server 106 can effectively determine that the modifiable content-segment is included in the content that the content-presentation device 104 is receiving and presenting. And because the modifiable content-segment is modifiable, the fingerprint-matching server 106 can facilitate the content-presentation device 104 performing a content-modification operation with respect to the modifiable content-segment.

As such, in response to detecting the match, the fingerprint-matching server 106 can perform an action that facilitates the content-presentation device 104 performing a content-modification operation. Examples of this action will now be described in more detail, and it should be understood that, in some situations, more than one of these example actions can be performed in response to detecting the match.

In some examples, the action can involve transmitting a transmission time-stamp to the content-presentation device 104 to facilitate the content-presentation device 104 using the transmission time-stamp to determine a modification start-time at which to perform the content-modification operation. As discussed above, the fingerprint-matching server 106 can determine the transmission time-stamp and transmit data (e.g., the “third metadata” referenced above) to the content-presentation device 104 that can be or include the transmission time-stamp. The content-presentation device 104 can then use the transmission time-stamp to determine the modification start-time at which to perform the content-modification operation. For instance, the content-presentation device 104 can account for the content-transmission delay by adding the content-transmission delay to the transmission time-stamp to arrive at the modification start-time.

In other examples, the action can also involve transmitting the starting frame marker to the content-presentation device 104 to facilitate the content-presentation device 104 using the transmission time-stamp and the starting frame marker to determine the modification start-time. As discussed above, the fingerprint-matching server 106 can determine the starting frame marker of the modifiable content-segment and transmit data (e.g., the “third metadata” referenced above) to the content-presentation device 104 that can be or include the starting frame marker. In some examples, the fingerprint-matching server 106 can determine and transmit an ending frame marker as well to facilitate the content-presentation device 104 determining a modification end-time, as also described above.

In other examples, the action can involve performing an action that facilitates the content-presentation device 104 retrieving supplemental content for use in connection with performing the content-modification operation.

By way of example, as discussed above, the fingerprint-matching server 106 can transmit supplemental content selection criteria that instructs the content-presentation device 104 to retrieve supplemental content that meets the selection criteria. For instance, the selection criteria can specify a type of supplemental content (e.g., a replacement content segment, overlay content, or other type), duration (e.g., 15 seconds, 30 seconds, or 60 seconds), aspect ratio (e.g., 4:3 or 16:9), and/or resolution (e.g., 720p or 1080p), among other possible criteria. This selection criteria can be in the third metadata described above or in other data transmitted from the fingerprint-matching server 106 to the content-presentation device 104. The content-presentation device 104 can then use the selection criteria to retrieve the supplemental content (e.g., request and download the supplemental content from the content-management system 108).

As another example, the fingerprint-matching server 106 might already have stored in memory the supplemental content or a link thereto for use in this scenario and can transmit the supplemental content or the link to the content-presentation device 104. As yet another example, the fingerprint-matching server 106 can retrieve the supplemental content or a link thereto (or other data identifying the supplemental content) from the content-management system 108 and transmit the supplemental content or the link to the content-presentation device 104. Other actions that facilitate the content-presentation device 104 retrieving the supplemental content are possible as well.

As discussed above, due to the content-transmission delay between when the content-distribution system 102 transmits content and when the content-presentation device 104 receives content, by the time the fingerprint-matching server 106 detects the match or performs the action, the content-presentation device 104 might have already begun presenting the modifiable content-segment. Thus, a content-replacement operation where the modifiable content-segment is replaced might not be possible. As such, the act of performing the action that facilitates the content-presentation device 104 performing the content-modification operation can involve performing an action that facilitates the content-presentation device 104 performing a content-modification operation other than a content-replacement operation. For example, the content-modification operation can be a DAI operation or other content-overlay operation. As another example, the content-modification operation can be an operation in which the content-presentation device 104 dynamically resizes the modifiable content-segment and inserts supplemental content to fill in any space left within the frame. As yet another example, the content-modification operation can be an operation in which the content-presentation device 104 cuts out a particular region of the modifiable content-segment (e.g., a square in a bottom-right corner) for at least a portion of the total duration of the modifiable content-segment and inserts supplemental content in that region. As yet another example, the content-modification operation can be an operation in which the content-presentation device 104 replaces a portion of the modifiable content-segment's duration with the supplemental content (e.g., however much of the modifiable content-segment's duration remains once the content-presentation device 104 initiates the content-modification operation). Other examples are possible as well.

The action that facilitates the content-presentation device 104 performing a content-modification operation other than a content-replacement operation can be or include any one or more of the actions described above.

As a more specific example of a content-overlay operation, consider a situation where the content-presentation device 104 receives content on a channel from the content-distribution system 102 and the content includes a replaceable advertisement segment and begins presenting the replaceable advertisement segment. The fingerprint-matching server 106 might not identify the channel to which the content-presentation device 104 is tuned, but might instead compare query fingerprint data received from the content-presentation device 104 representing the replaceable advertisement segment with reference fingerprint data that also represents the replaceable advertisement segment. As a result, the fingerprint-matching server 106 will detect a match, thus effectively determining that the replaceable advertisement segment has been received by the content-presentation device 104. Although a content-replacement operation might not be possible, the fingerprint-matching server 106 can perform one or more actions that enable the content-presentation device 104 to retrieve overlay content and begin overlaying the overlay content on the replaceable advertisement segment at a start-time that follows the time-point at which the content-presentation device 104 began presenting the replaceable advertisement segment. The overlay content can then be displayed for a remaining duration of the replaceable advertisement segment or for a portion of the remaining duration. Other example scenarios are possible as well.

As discussed above, there might be situations where the channel is not identified but there is still enough time to perform a content-replacement operation. For example, the content-presentation device 104 might receive content including the modifiable content-segment, generate and send query fingerprint data to the fingerprint-matching server 106, but not yet begin presenting the modifiable content-segment, such as by temporarily storing received content, including the modifiable content-segment, in a buffer. Thus, the fingerprint-matching server 106 might have enough time to perform an action that facilitates the content-presentation device 104 replacing the modifiable content-segment with a replacement content segment. Other examples are possible as well.

FIG. 5 is a flow chart of an example method 500. At block 502, the method 500 includes receiving query fingerprint data representing content received by a content-presentation device.

At block 504, the method 500 includes making a first comparison of at least a first portion of the received query fingerprint data with at least one first reference fingerprint data set, where each of the at least one first reference fingerprint data sets corresponds with a respective channel identifier.

At block 506, the method 500 includes based on the first comparison, determining that the received query fingerprint data does not match any of the at least one first reference fingerprint data sets.

At block 508, the method 500 includes responsive to the determining, making a second comparison of at least a second portion of the received query fingerprint data with second reference fingerprint data representing a modifiable content-segment.

At block 510, the method 500 includes based on the second comparison, detecting a match between at least the second portion of the received query fingerprint data and the second reference fingerprint data.

At block 512, the method 500 includes responsive to detecting the match, performing an action that facilitates the content-presentation device performing a content-modification operation.

The method 500 and related acts can be performed at least in part by the fingerprint-matching server 106. In some implementations, the method 500 and related acts can be performed at least in part by another device within the content-modification system 100.

As described above, implementations of the disclosed methods and systems provide technological improvements that are particular to computer networks and computing systems, for example, content-modification systems such as content-modification system 100.

IV. Example Variations

Although the examples and features described above have been described in connection with specific entities and specific operations, in practice, there are likely to be many instances of these entities and many instances of these operations being performed, perhaps contemporaneously or simultaneously, on a large-scale basis. Indeed, in practice, the content-modification system 100 is likely to include many content-distribution systems (each potentially transmitting content on many channels) and many content-presentation devices, with some or all of the described operations being performed on a routine and repeating basis in connection with some or all of these entities.

In addition, although some of the operations described in this disclosure have been described as being performed by a particular entity, the operations can be performed by any entity, such as the other entities described in this disclosure. Further, although the operations have been recited in a particular order and/or in connection with example temporal language, the operations need not be performed in the order recited and need not be performed in accordance with any particular temporal restrictions. However, in some instances, it can be desired to perform one or more of the operations in the order recited, in another order, and/or in a manner where at least some of the operations are performed contemporaneously/simultaneously. Likewise, in some instances, it can be desired to perform one or more of the operations in accordance with one more or the recited temporal restrictions or with other timing restrictions. Further, each of the described operations can be performed responsive to performance of one or more of the other described operations. Also, not all of the operations need to be performed to achieve one or more of the benefits provided by the disclosure, and therefore not all of the operations are required.

Although certain variations have been described in connection with one or more examples of this disclosure, these variations can also be applied to some or all of the other examples of this disclosure as well and therefore aspects of this disclosure can be combined and/or arranged in many ways. The examples described in this disclosure were selected at least in part because they help explain the practical application of the various described features.

Also, although select examples of this disclosure have been described, alterations and permutations of these examples will be apparent to those of ordinary skill in the art. Other changes, substitutions, and/or alterations are also possible without departing from the invention in its broader aspects as set forth in the following claims. 

What is claimed is:
 1. A method comprising: receiving query fingerprint data representing content received by a content-presentation device; making a first comparison of at least a first portion of the received query fingerprint data with at least one first reference fingerprint data set, wherein each of the at least one first reference fingerprint data sets corresponds with a respective channel identifier; based on the first comparison, determining that the received query fingerprint data does not match any of the at least one first reference fingerprint data sets; responsive to the determining, making a second comparison of at least a second portion of the received query fingerprint data with second reference fingerprint data representing a modifiable content-segment; based on the second comparison, detecting a match between at least the second portion of the received query fingerprint data and the second reference fingerprint data; and responsive to detecting the match, performing an action that facilitates the content-presentation device performing a content-modification operation.
 2. The method of claim 1, wherein at least the first portion of the received query fingerprint data and at least the second portion of the received query fingerprint data are the same.
 3. The method of claim 1, further comprising: determining a transmission time-stamp representing a time-point at which a content-distribution system transmitted the modifiable content-segment, wherein performing the action comprises transmitting the transmission time-stamp to the content-presentation device to facilitate the content-presentation device using the transmission time-stamp to determine a modification start-time at which to perform the content-modification operation.
 4. The method of claim 3, further comprising: determining a starting frame marker of the modifiable content-segment, wherein performing the action further comprises transmitting the starting frame marker to the content-presentation device to facilitate the content-presentation device using the transmission time-stamp and the starting frame marker to determine a modification start-time at which to perform the content-modification operation.
 5. The method of claim 1, wherein performing the content-modification operation comprises performing a content-modification operation other than a content-replacement operation.
 6. The method of claim 5, wherein performing the content-modification operation comprises performing a content-overlay operation.
 7. The method of claim 6, wherein performing the action further comprises performing an action that facilitates the content-presentation device retrieving overlay content for use in connection with performing the content-overlay operation.
 8. The method of claim 7, wherein performing the action that facilitates the content-presentation device retrieving the overlay content for use in connection with performing the content-overlay operation comprises transmitting, to the content-presentation device, supplemental content selection criteria that instructs the content-presentation device to retrieve the overlay content.
 9. The method of claim 1, wherein the method is performed by a fingerprint-matching server of a content-modification system.
 10. A non-transitory computer-readable storage medium, having stored thereon program instructions that, upon execution by a processor, cause performance of a set of operations comprising: receiving query fingerprint data representing content received by a content-presentation device; making a first comparison of at least a first portion of the received query fingerprint data with at least one first reference fingerprint data set, wherein each of the at least one first reference fingerprint data sets corresponds with a respective channel identifier; based on the first comparison, determining that the received query fingerprint data does not match any of the at least one first reference fingerprint data sets; responsive to the determining, making a second comparison of at least a second portion of the received query fingerprint data with second reference fingerprint data representing a modifiable content-segment; based on the second comparison, detecting a match between at least the second portion of the received query fingerprint data and the second reference fingerprint data; and responsive to detecting the match, performing an action that facilitates the content-presentation device performing a content-modification operation.
 11. The non-transitory computer-readable storage medium of claim 10, wherein at least the first portion of the received query fingerprint data and at least the second portion of the received query fingerprint data are the same.
 12. The non-transitory computer-readable storage medium of claim 10, the set of operations further comprising: determining a transmission time-stamp representing a time-point at which a content-distribution system transmitted the modifiable content-segment, wherein performing the action comprises transmitting the transmission time-stamp to the content-presentation device to facilitate the content-presentation device using the transmission time-stamp to determine a modification start-time at which to perform the content-modification operation.
 13. The non-transitory computer-readable storage medium of claim 10, wherein performing the content-modification operation comprises performing a content-modification operation other than a content-replacement operation.
 14. The non-transitory computer-readable storage medium of claim 13, wherein performing the content-modification operation comprises performing a content-overlay operation.
 15. The non-transitory computer-readable storage medium of claim 14, wherein performing the action further comprises performing an action that facilitates the content-presentation device retrieving overlay content for use in connection with performing the content-overlay operation.
 16. A computing system comprising: a processor; and a non-transitory computer-readable storage medium, having stored thereon program instructions that, upon execution by the processor, cause performance of a set of operations comprising: receiving query fingerprint data representing content received by a content-presentation device; making a first comparison of at least a first portion of the received query fingerprint data with at least one first reference fingerprint data set, wherein each of the at least one first reference fingerprint data sets corresponds with a respective channel identifier; based on the first comparison, determining that the received query fingerprint data does not match any of the at least one first reference fingerprint data sets; responsive to the determining, making a second comparison of at least a second portion of the received query fingerprint data with second reference fingerprint data representing a modifiable content-segment; based on the second comparison, detecting a match between at least the second portion of the received query fingerprint data and the second reference fingerprint data; and responsive to detecting the match, performing an action that facilitates the content-presentation device performing a content-modification operation.
 17. The computing system of claim 16, wherein at least the first portion of the received query fingerprint data and at least the second portion of the received query fingerprint data are the same.
 18. The computing system of claim 16, wherein performing the content-modification operation comprises performing a content-modification operation other than a content-replacement operation.
 19. The computing system of claim 18, wherein performing the content-modification operation comprises performing a content-overlay operation.
 20. The computing system of claim 19, wherein performing the action further comprises performing an action that facilitates the content-presentation device retrieving overlay content for use in connection with performing the content-overlay operation. 